Empiricism and model building in stratigraphy: The historical roots of present-day practices

摘要: The science of Stratigraphy has, since its inception in the late eighteenth century, been characterized by two contrasting research modes or "cognitive styles" (Rudwick 1982). Empirical (inductive) descriptive stratigraphy began with William Smith, led to establishment a data base stratigraphic units (Murchison, Sedgwick, Lapworth), and formed basis for modern work es- tablish refine detailed chronostratigraphic time scale (Van Hinte, Berggren). Other workers (Hutton, Lyell, Darwin, Chamberlin, Ulrich, Umbgrove, Sloss, Vail) have sought identify underlying geological controls, built deductive models explain earth processes, beginning Hutton's uniformitarianism. Many such evidence regularity cyclicity processes ("the pulse earth"), including "global-eustasy" model Vail. There is an ever present danger that can drive analysis presentation data, particularly where invoked explain, clarify codify record. These problems are not new. Attempts apply European North American early twentieth century were accompanied expectations unit boundaries would be marked lithologic events, as unconformities. supported, this may attempts establish alternative stratigraphies, what became sequence stratigraphy. Ulrich (1911) thought successions created "diastrophic cycles", was concerned regional correlations these did appear supported biostratigraphic evidence. Barrell (1917) one first understand prob- lems lack representation long intervals geologic record, developed ideas concerning relation- ship between level change sedimentation we now term "accommodation." Modern on based empirical principles, culminating definition global section boundary stratotypes major units. However, controversy has recently arisen over preference some geologists use distinctive marker events define boundaries. In cases, involves introducing hypotheses about extent superiority rather than relying accumulated historical record other data.